The invention relates to a method for producing an adhesive-bound printed item composed of several printed products, for which the printed products are gathered into loose book blocks along a first conveying section of a conveying track for a circulating conveyor and are then supplied with the aid of a following conveying section to an adhesive binder. The invention furthermore relates to an arrangement for realizing said method.
With known methods used in the print processing industry for the adhesive binding of printed products to form printed items, the individual printed products are first gathered to form loose book blocks inside a gathering machine and are subsequently transferred to the conveying clamps of an adhesive binder. The transfer from the gathering machine to the adhesive binder among other things involves the function of taking over the gathered loose book blocks, which move at the speed and with the orientation of the gathering machine, and to transfer these book blocks to the adhesive binder at the speed of the adhesive binder.
According to one known machine of the above type, the book blocks are conveyed inside the gathering machine in the direction of the book block spine, meaning inside a channel with a V-shaped cross section that is inclined slightly toward the back folds. The book blocks are transferred while positioned in a vertical plane to the adhesive binder, which is also moving in a longitudinal direction, wherein the back folds of the book blocks are directed downward. In the gathering machine, the book blocks are normally conveyed form-fittingly and transferred with the aid of pushers attached to chains, which push along the book blocks. If the book blocks in the transfer region do not require any optional processing, for example vibrating, adding sections and gluing on end sheets, wire-stitching, printing, and the like, the book blocks only need to be moved from a slightly inclined position to an upright position during the conveying in the longitudinal direction of the spine. In the event that the gathering machine stops, the adhesive binder can continue the processing of the remaining book blocks inside the adhesive binder with the aid of a transfer element, which transfers the book blocks from the gathering chain of the gathering machine to a conveying chain for the intake area of the adhesive binder. The transfer element can furthermore be used to compensate for speed differences resulting from differences in the divisional spacing between the gathering machine and the adhesive binder. This solution is quite simple, but has the disadvantage that the printed products are conveyed in the direction of their greatest length. As a result, the spacing between successive book blocks of necessity increases and the conveying speed becomes relatively high. The conveying speed can thus form the maximum possible production speed. Above all, this is true for the channel region of the gathering machine in which air turbulence is generated as a result of the conveying operation, which then generates buoyancy forces in the uppermost printed products of the loose book block and can lift these off the book block. Another disadvantage manifests itself when the gathering machine is stopped because the loose book blocks shoot forward toward the next pusher as a result of their kinetic energy, thereby losing their orientation which can result in poor products or machine breakdowns.
According to a further known machine of the above type, the book blocks are gathered and conveyed inside a vertical channel, thus making it possible to omit the movement for putting the book blocks in the upright position. However, the aforementioned features and disadvantages apply in this case as well.
According to the disclosure in European Patent Application 0 675 005 B1, the loose book blocks are conveyed inside the adhesive binder while positioned transverse to the longitudinal spine direction. It is therefore conceivable to gather the printed products in the gathering machine while positioned transverse to the longitudinal direction and to subsequently transfer these to the adhesive binder moving in the transverse direction. As a result, the conveying speed can be reduced while the production speed is maintained, as compared to a conveying in the longitudinal direction of the spine. This solution has the disadvantage of a complicated design for the adhesive binder because a relative movement between the processing tools and the book blocks is necessary for some processing operations in the longitudinal spine direction.
According to another known machine, the printed sheets are gathered along a conveyor belt while positioned transverse to the longitudinal direction of the spine in an overlapping flow and are deposited one above the other. The individual book blocks are then separated out of the overlapping flow just prior to being transferred to an adhesive binder moving in the longitudinal direction. As disclosed in European Patent Application 1 528 023 A1, the book blocks can be transferred to laterally moving compartments following the separation and can be pivoted to the upright position, so that the book block spines are oriented in a downward direction. The book blocks can then be transferred with the aid of a 90° translational deflection to a conveyed flow moving in the longitudinal direction of the spine. This solution combines the advantages of a gathering machine, moving transverse to the longitudinal direction of the book block spine with the advantages of an adhesive binder moving in longitudinal direction of the spine. The disadvantage of this method, however, is that thicker book blocks, book blocks having a smaller format, and book blocks with a rigid content such as a CD-ROM, cannot be processed. The method furthermore restricts the positions that can be occupied by smaller printed products within a book block.